1. Field of the Invention
The present invention relates to a cartridge case for holding a disk-shaped recording medium in such a way that the recording medium can rotate freely inside the cartridge case and that the recording medium can be put into and taken out of the cartridge case easily for the purpose of loading the recording medium together with the cartridge case holding it into a disk drive device.
In addition, the present invention relates also to a disk cartridge that holds a disk-shaped recording medium in a cartridge case in such a way that the recording medium can rotate freely inside the cartridge case and that the recording medium can be put into and taken out of the cartridge case easily.
2. Description of the Prior Art
For the purpose of loading a disk-shaped recording medium such as an optical disk into a disk drive device, a cartridge case is used that holds the disk-shaped recording medium in such a way that the recording medium can rotate freely inside the cartridge case and that the recording medium can be put into and taken out of the cartridge case easily. Conventionally, this type of cartridge case has on its top side an opening through which the disk-shaped recording medium is put into and taken out of the cartridge case, and has on its bottom side a head access window through which a head for writing and reading data to and from the recording medium is inserted into the cartridge case and a drive spindle access window through which a drive spindle for rotating the recording medium is inserted in the cartridge case. The cartridge case consists essentially of a box-shaped cartridge case body that holds the disk-shaped recording medium in such a way that the recording medium can rotate freely in the cartridge case body, a shutter that is fitted to the cartridge case body in such a way that it can slide along the front edge of the cartridge case body to open and close the head access window and the drive spindle access window, and a lid that is fitted in one edge of the cartridge case body in such a way that it can be flipped into and out of the above-mentioned opening.
In recent years, disk-shaped recording media having recording surfaces on both sides have come into common use. However, using the conventional cartridge case described above to record and reproduce data to and from such a double-sided recording medium causes much trouble, because in such a case it is inevitable, on completion of data recording or reproduction to or from one side, to unload the cartridge case from the disk drive device, take the recording medium out of the cartridge case, reverse the recording medium, put the recording medium in the cartridge case again, and load the cartridge case into the disk drive device again.
To make such temporary removal and reversing of the recording medium unnecessary, it is possible to devise, for example, a cartridge case that has head access windows and drive spindle access windows on both sides. However, if this is attempted on the basis of the structure of the conventional cartridge case described above, the resulting cartridge case will require a complicate structure of the shutter and thus demand higher production cost. Specifically, since the head access window and drive spindle access window are provided not only in the cartridge case body but also in the lid, the shutter needs to be designed to have a U-shaped cross section so that it has a pair of shuttering portions, i.e. one for the head access window and drive spindle access window on each side. In addition, since the lid is, as described above, rotatable, one of those shuttering portions also needs to be designed to be rotatable. This makes the structure of the shutter extremely complicate and thus greatly increases cost and labor required for its production.
Moreover, a disk cartridge of the type that holds a disk-shaped recording medium in such a way that the recording medium can be put into and taken out of the cartridge case freely tends to cause its user to damage the recording surface of the recording medium with a scratch or other when the recording medium is being put into or taken out of the cartridge case, causing reading or writing errors. This makes it extremely difficult to verify whether the damage results from mishandling on the part of the user or not, to the manufacturer's disadvantage.